The moon turns around the Earth.
The Earth turns around the Sun.
Does the Sun turn around a big star?
If so, does this big star turn around a very big star?
... etc ...
What are all the intermediate ...

The Sun's rays hit our eyes around 8 minutes after they are emitted from the Sun.
Does this mean that the Sun that we see is always the Sun as it was some 8 minutes before? I strongly think this must ...

The planets rotate as an after effect of their creation, the dust clouds that compressed span as they did so and the inertia has kept it rotating ever since.
It's fairly easy to prove that planetary ...

Now that the Gaia Space Telescope is on it's way to the Sun-Earth L2 Lagrangian point (SEL2), I start wondering about the stability of Gaia's orbit there. The Planck Telescope is already there, as was ...

Since Jupiter is very massive, it is the only planet (in our solar system) that has a center of mass with the Sun that lies outside the volume of the Sun. (Source)
If Jupiter was a star, they would ...